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Biomedical subjects

M Wada

Publications and source records attributed to M Wada.

At least 739 records · Page 41Linked to original sources
PubMed1976

Immunohistochemical localization of LH-producing cells in the adenohypophysis of the Japanese quail, Coturnix coturnix japonica.

The cells that produce luteinizing hormone (LH) in the adenohypophysis of the Japanese quail were identified immunohistochemically using anti-chicken LH serum and horseradish peroxidase-labeled goat anti-rabbit gamma globulin serum. The LH cells are localized in the caudal lobe of the pars distalis. They are elongate in shape shape and are polarized toward the sinusoids, especially in their active states. Alterations in size of LH cells are directly related to changes in circulating LH levels as induced by castration or photostimulation. The LH cells identified immunohistochemically were only stained by alcian blue with periodic acid-Schiff (PAS), alcian blue and orange G. PAS-positive gonadotropic cells in the cephalic lobe were stained immunohistochemically only slightly if at all using anti-chicken LH serum and consequently may be FSH producing cells. In the cephalic lobe another type of basophilic cell was stained with alcian blue. These cells were also stained immunohistochemically with anti-chicken LH serum. These cells may possibly be identified as TSH cells due to the characteristics of the anti-chicken LH serum used in this study which cross react with LH and TSH but only slightly with FSH, and also on the basis of previous light and electron microscopic studies.

Alcian Blue↗
PubMed1976

Mechanism of D-alanine production by Corynebacterium fascians.

The amounts of extracellular D-alanine accumulated by Corynebacterium fascians ATCC 21950 in a medium containing glycerol as the sole carbon source is increased to almost 12 mg/ml by adding pyruvate to the medium. Cell-free extracts of C. fascians were shown to possess both L-alanine dehydrogenase and alanine racemase activities. These results indicated that a mechanism exists that allows this microorganism to synthesize D-alanine from pyruvate. A study comparing the optical purity of the intracellular alanine and the extracellular alanine suggested that the cell membrane possesses the stereospecific permeability for D-alanine. Thus, it may be concluded that L-alanine is first formed from pyruvate by L-alanine dehydrogenase and then converted to D-alanine by racemase inside the cells. Subsequently, only D-alanine leaks out stereospecifically through the cell membrane, and large amounts of D-alanine accumulate in the extracellular medium.

Alanine↗
PubMed1976

Experimental studies on the antiarrhythmic action of a lidocaine analog.

The electrophysiologic properties of a lidocaine analog (Kö 1173) was experimentally studied in 41 mongrel dogs. The threshold for occurrence of repetitive ventricular extrasystoles was significantly raised by the administration of 2, 4, and 8 mg/kg of the drug, while atrioventricular and intraventricular conduction times were not affected. After ligation of the anterior descending branch of the left coronary artery, the threshold for occurrence of repetitive ventricular extrasystoles was significantly lowered before the administration of Kö 1173 but it returned to control values after the administration 1 mg/kg of the drug. The strength-interval curve shifted profressively to the right when the dose was increased from 2 to 4 and 8 mg/kg. These results indicate that Kö 1173 prevents the decrease in threshold for occurrence of repetitive ventricular extrasystoles in acute coronary insufficiency at a dose which does not affect the conduction system.

Animals↗
PubMed1976

Effects of hyperosmolarity on the cyclic AMP concentration and lipolysis of the adipocyte stimulated by adrenocorticotropic hormone.

The effects of ACTH on 3',5'-cyclic AMP (cAMP) levels and lipolysis were examined on isolated adipocytes incubated in either isosmolar or hyperosmolar media. The ability of ACTH to induce intracellular cAMP accumulation was greatly enhanced by incubating cells in hyperosmolar sucrose (100 to 400 mM) solutions. Hyperosmolar solutions prepared by the addition of either NaCL, glucose or mannitol enhanced the ACTH effect on cAMP to the same extent as did the hyperosmolar sucrose solution, but hyperosmolar urea solutions did not have such an effect. The effect of hyperosmolarity was shown only in cells stimulated by lipolytic hormones, and the effects were still evident in the presence of high concentrations of theophylline, indicating the effect of hyperosmolarity is to facilitate hormone action on the receptor-coupler system of the adipocyte membrane. The action of glucagon on cAMP was augmented much less than the actions of ACTH and isoproterenol. Basal as well as ACTH or exogenous cAMP stimulated lipolysis was lower in hyperosmolar sucrose solutions. Some mechanism by which hyperosmolarity interferes with the metabolic sequence beyond the accumulation of cAMP was suggested.

Adipose Tissue↗
PubMed1976

A female case of Kallmann's syndrome.

A case of 20-year-old woman with hypogonadotropic hypogonadism and anosmia is reported, since very few female cases of Kallmann's syndrome have been reported so far in Japan. Three uncles on the father's side had no children. Height was 168 cm, and arm span 165 cm. The olfactory test revealed complete anosmia. Bone age was 13 year. Chromosome was 46 XX and normal karyotype. Basal levels of serum FSH, LH and estrogens (E1, E2 and E3) were low. Serum FSH and LH levels rose slightly only after LH-RH administration, and did not increase in clomiphene test. Plasma estrogens did not increase after daily injection of 150 IU of HMG for 3 successive days. The response of serum GH to arginine infusion was normal, while that to insulin-induced hypoglycemia was poor.

Adult↗
PubMed1975

Cell types in the adenohypophysis of the Japanese quail and effects of injection of luteinizing hormone-releasing hormone.

The cells of the adenohypophysis of the Japanese quail were studied by both light and electron microscopy after exposure to long photoperiods or injection of lutenizing hormone-releasing hormone (LRH). Six cell types were identified in the adenohypophysis by examining alternate thick and thin sections by light and electron microscopy. In the cephalic lobe, there are four types of glandular cells. They are the prolactin cells, ACTH cells, TSH cells, and gonadotropic cells (FSH?). In the caudal lobe, there are two types of cells, STH cells and gonadotropic cells (LH?). After exposure to long daily photoperiods, gonadotropic cells in both lobes were strongly activated. They became larger and accumulated many granules. ACTH cells became vacuolated; granules were sparse. Synthetic LRH injection (10 mug/0.2 ml/day) for 10 days to the non-photostimulated quail stimulated certain numbers of the gonadotropic cells in the both lobes, although the response of the cells was less than that induced by photostimulation. No response was seen in the other cell types.

Adrenocorticotropic Hormone↗